HOW TECHNICAL DOCUMENTS SAVE MILLIONS OF EUROS
Text: Thomas Masuch; Photos: Fraunhofer IGCV — 2019/09/09
Smoother product launches, cost savings in the millions, leaner processes, plus more reliable relationships between customers and suppliers: This may sound like little more than a dream for the world of additive manufacturing, but it is set to become reality – thanks to many new and globally applicable standards. International and national committees have teamed up under the dual logo of ISO-ASTM standards to create a large number of new documents spanning the entire process chain. Some have already been published, and many will soon follow.
In themselves, standards may not be particularly spectacular, but they are currently a hot topic internationally. The two associations with the greatest international power, ASTM and ISO, have joined forces to collaborate with key representatives of the AM industry – from system manufacturers and software vendors right through to users of AM technology. Many international working groups are going through an entire roadmap of processes to establish the corresponding standards. There are five core areas in which it is particularly important to close existing gaps: design, qualification and certification, process and material, non-destructive testing, and maintenance.
Professor Christian Seidel, Chairman of ISO/TC 261, also knows from his own professional experience that vast potential savings can be achieved through appropriate standards – for example, in the aviation industry: »In the past, components were tested again and again to prove that they are safe. Individual companies spent millions of euros on material and component tests, partly because no corresponding standards were available at the time,« says Seidel, who is a full-time professor of manufacturing technology and additive processes at Munich University of Applied Sciences and head of additive manufacturing at the Fraunhofer IGCV in Augsburg. If this total is extrapolated to users and manufacturers in Europe and worldwide, standards can save hundreds of millions of euros. But standards not only help save costs, they also streamline internal processes. »What other criteria can employees use to govern the use of additives in manufacturing processes within a company – for example, when it comes to ensuring consistent quality?« asks Seidel. »Arguing for your approach by saying you have the best experience in the field is often not enough.
RELIABLE DESIGN WORK
Just how useful ISO and ASTM’s work can be in this area is shown, for example, by the ISO ASTM 52911 »design standard«, which provides a technical design guideline for powder bed fusion processes in additive manufacturing.1 It includes information about overhangs that should have support structures, about the permissible size of cavities and internal channels or the thinness of walls. According to Seidel, this standard is important for external service providers, who can use it to certify reliable design work to their customers. In addition, guidelines of this kind can deliver significant benefits within companies: »For example, you could specify that a design is to be created according to this standard, with company-specific deviations being permitted in certain areas, of course. That would appreciably reduce the effort required for tasks and project descriptions,« explains Seidel.
To date, 12 standards have been published under the dual logo, and a further 54 are currently in progress and will follow soon. The published ISO/ASTM standards are generally adapted as European standards and replace all existing national documents in Europe with the same content.
The new standards will help the entire industry and internationally working companies immensely. It also lowers the barriers to new companies entering the market, which would certainly lead to a large number of new applications. What’s more, standards can help establish a reliable relationship between customers and suppliers for additive applications.
Seidel also sees ISO/ASTM 52902 as a »valuable guideline« for checking machine accuracy with test pieces. Among other things, this standard defines thin walls and slots, a hole with a diameter of 1 mm, or a rod-shaped pin structure with a thickness of 1 mm. »Companies wishing to assess the accuracy of their own machines or a machine they intend to purchase can use the structures described in ISO/ASTM 52902 for comparative tests,« explains Seidel. »After all, some 3D printing systems deliver different levels of accuracy, depending on the positioning of the component in the modeling area.«
The technical specifications of the standards are the result of consensus between major players and experts. They already play an important role in basic and further training programs. »In the case of the ISO/ASTM standards, for example, there is very strong international consensus between some 30 countries that are entitled to comment before publication,« Seidel said.
OCCUPATIONAL SAFETY: HIGH AVOIDABLE COSTS
STS Standards can also answer many open questions in the field of occupational safety, which has become increasingly important in the world of additive manufacturing in recent years. These questions include: What dangers exist, how do you identify them, and how do you deal with them? And they cover areas ranging from powder to personal protective equipment and air pollution control. »Companies typically invest a lot of time in introducing technology,« explains Seidel. »In our experience, it takes a great deal of coordination with internal and external representatives to find answers to questions relating to occupational safety. Examples include the air-exchange rate for ventilation, handling of hazardous substances, and so on. Having an independent document based on technical consensus can save days of work and make it much easier to get started with the technology.«
Technical Committee 105.6 of the Association of German Engineers (VDI), which focuses on safety during the operation of additive manufacturing systems, has therefore been dedicated to this topic since 2016 and has published a highly regarded resource on laser beam melting technology in the form of VDI 3405 Sheet 6.1. According to Seidel, another document on laser sintering will be available at the end of 2019.
1 This refers to the technologies electron beam and laser melting for metal, and laser sintering for plastics.
AM Standards Forum
The international AM Standards Forum, which celebrated its premiere at Formnext 2018, will continue at Formnext 2019 on 19 November at 2:00 p.m. The forum is organized by Formnext in cooperation with the U.S. Commercial Service.